It's not always about lifting the heaviest possible weight...you can build muscle with your own body weight and isolation exercises and your more likely to remain injury free. The amount of times I see people training biceps with massive weights but with no form...then they complain their arms aren't growing!!? That's because they are mostly using their backs! Don't be macho and out of proportion, be smart and symmetric!
Every muscle including your Abs needs sufficient time to recover properly! The gym isn't meant to be for defining your jaw line by catching up on the latest gossip! Get in, focus on the muscle being trained and keep yourself motivated with music if needs be! This will prevent too many disruptions/distractions! Try and keep it under and hour with small rest periods (pending on cutting or bulking).
Drinking water is essential for anyone but more so for the training enthusiasts! Dehydration or dropping water is not the way forward! You need water to flush the system, help sweat, prevent cramping along with helping energy levels and your skin complexion.
If you don't have a goal to score in, how can you win!? You need to set yourself a target to keep motivated. Observing progression is the key to staying on top. If you don't know what you want then your wasting your time...your training and nutrition needs to be synced.
Eat your way to success! There's no need to take any type of illegal supplements, just become more prepared and knowledgeable... there are plenty of ways to get big or ripped with legal supplements (like Reflex Nutrition) and a good progressive training and nutrition programme...believe in yourself and the gains will follow.